The invention relates to a magnetic device for extracting ferrous particles from a body of fluid. More particularly, the present invention is directed to a high strength magnetic device that is suitable for use within a housing, conduit or the like through which fluids flow. The invention also relates to an assembly utilizing the magnetic device for the extraction of ferrous particles from a body of fluid.
In industry, it is frequently necessary to remove ferrous particulate contaminants from liquids, such as, for example, lubricating oils, coolant fluids, water, fuels, pump fluids and hydraulic fluids. The use of magnets for this purpose has long been recognized. Attempts have been made to provide a device in which a rod-type magnetic assembly is placed within a cylindrical vessel through which fluid flows, including the devices disclosed in U.S. Pat. Nos. 4,026,805; 4,176,065, 4,450,075; and 4,883,591. These devices operate on the principle that ferrous particles adhere to the magnetic assembly by magnetic attraction and are thereby isolated from the body of fluid.
The devices indicated above, and other similar devices, however, collectively present a number of drawbacks. For example, they may utilize low strength magnets, may not offer ease of cleaning, or may be constructed of non-ferrous metal that may allow a dangerous electrical build-up and transfer. In addition, none of the previously disclosed devices are suitable for use with gearbox applications, as they generate a magnetic field around the entire magnetic device including one from the tip resulting in the magnetization of the ferrous gear or shaft and trapping of ferrous contaminants thereon.
Previous assemblies that employ magnetic rods for fluid treatment often include screens, baffles or rings so that there is a resultant restriction to fluid flow. These assemblies require complex bypass systems including pressure release valves. Furthermore, many previous devices result in essentially laminar flow of fluid along the length of the magnetic rod such that filtration of the fluid is inefficient. Finally, some of the previously disclosed devices are designed for specific uses and as such are not adaptable to a variety of systems for which extraction of ferrous particulate contaminants is desired.
The present invention provides a reusable high strength magnetic device for the removal of ferrous particulate contaminants from a body of fluid. The device can be removably installed within the interior of a wide variety of fluid containing systems, such as, for example oil filters, fuel reservoirs, hydraulic pumps, gearboxes, and gas lines. The device is easy to clean and is resistant to corrosion. The magnetic device creates a magnetic field radially about it but does not generate a magnetic field about its long axis, beyond at least one end of the device.
Further, the invention provides a magnetic filter assembly that results in turbulent flow of fluid around the magnetic device such that the fluid is forced to come in full contact with the magnetic field resulting in full filtration of the ferrous contaminants. In one embodiment, the assembly generates a spiral fluid flow path. The spiral flow offers a reasonably long flow path in a compact device. In addition, the assembly has an internal cross sectional area that tends not to restrict the flow path of the fluid or require bypass systems including pressure release valves.
Accordingly, a broad aspect of the present invention provides a reusable magnetic device for the extraction of ferrous particles from a body of fluid, wherein the device comprises a plurality of magnets and soft ferrous metal spacers arranged in an alternating sequence to form a stack, adjacent magnets being arranged with like poles facing, a non-magnetic and non-ferrous end piece terminally disposed at a first end of the stack, and a non-magnetic housing that contains the magnets, the spacers and the end piece.
In accordance with another broad aspect of the invention there is provided a reusable magnetic device for the extraction of ferrous particles from a body of fluid, wherein the device comprises a plurality of magnets and soft ferrous metal spacers arranged in an alternating sequence to form a stack, adjacent magnets being arranged with like poles facing, a non-magnetic and non-ferrous end piece terminally disposed at a first end of the stack and a non-magnetic housing that contains the magnets, the spacers and the end piece, the end piece being selected such that a magnetic field is not present at the terminal tip of housing adjacent the end piece, and means for removeably attaching the rod inside a vessel containing the body of fluid on the housing at a second end opposite the first end.
In accordance with yet another broad aspect of the invention, there is provided a magnetic filter assembly for the extraction of ferrous particles from a body of fluid comprising a magnetic rod including a plurality of magnets and soft ferrous metal spacers arranged in an alternating sequence to form a stack, adjacent magnets being arranged with like poles facing, a non-magnetic and non-ferrous end piece terminally disposed at a first end of the stack, and a non-magnetic housing that contains the magnets, the spacers and the end piece, the end piece being selected such that a magnetic field is not present at the terminal tip of housing adjacent the end piece; and a cylindrical vessel within which the magnetic rod is removeably mounted, the vessel having fluid inlet adjacent its first end and a fluid outlet adjacent its second end.